1. Field of the Invention
The present invention relates to an image-recording medium, which allows a printed material that has adhered thereto upon formation of an image by using a copying machine or a printer, etc. to be removed therefrom, and which is recyclable repeatedly. In particular, the present invention relates to such an image-recording medium that is suitable for a removing means using a physical frictional force, such as a brushing method using an aqueous solvent like water.
2. Description of the Related Art
In recent years, along with the development of the electrophotographic copying (so-called copying) technology using toner, a great amount of image-recording media such as paper and OHP sheets have been used.
The printed materials, printed or copied on these image-recording media, are difficult to be removed therefrom and such a technology has not been put into practical use; therefore, a great amount of printed materials that have been generated in offices are disposed as wastes when they are no longer used.
It is clear that this situation is not preferable from the standpoint of environmental preservation and protection of resources. For this reason, the technique for reproducing and recycling these image-recording media to be disposed as wastes has been studied hard. For example, Japanese Patent Application Laid-Open No. 222604/1994 has disclosed an image-recording medium in which a swelling layer that is allowed to swell with water is formed on the entire surface of a base layer such as a resin film, paper, metal foil, etc., and this swelling layer is moistened with water to swell so that images recorded on the image-recording media are removed.
The technology of this type is very useful as a method for reproducing unnecessary image-recording media, from the viewpoint of energy and costs. In the image-recording media having such a structure, it is possible to remove all the printed materials printed on the surface thereof, and to recycle the resulting image-recording media.
There have been demands for removing printed image not from the entire surface of the image-recording media but from only one portion thereof so as to recycle the image-recording media. For example, in most cases, platforms such as frames of lists, headlines and company names are common portions, and if the printed characters are removed from the entire surface, the portions using the same character forms and designs need to be reprinted each time recycled, causing a wasteful use of materials for printing and an increase in time-consuming tasks. Therefore, there have been demands for techniques for selectively removing images printed on image-recording media.
In the case of the image-recording medium having the structure disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 222604/1994, the printed material on the entire surface is removed, it being impossible to selectively remove the printed material.